template-only-components

components.my-component\.hbs

{{log "Colocated this: " this}}
<h1>ColocatedTemplate Only Component</h1>

controllers.application\.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
}

templates.application\.hbs

<p>
This twiddle shows that Colocated Template Only components are _always_ Glimmer Components, regardless of whether the <code>template-only-glimmer-components</code> feature is turned on or off.
</p>
<p>Open JS console to see that the <code>this</code> context is <code>null</code> for the colocated component regardless of the value of the <code>template-only-glimmer-components</code> optional feature. You can toggle the feature in twiddle.json
</p>
<MyComponent />
<ClassicComponent />

templates.components.classic-component\.hbs

{{log "classic this: " this}}
<h1>Classic Template Only Component</h1>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}